SCADA worm a 'nation state search-and-destroy weapon'

A highly sophisticated computer worm that has burrowed into industrial systems worldwide over the past year may have been a “search-and-destroy weapon” built to take out Iran's Bushehr nuclear reactor, according to news reports published on Tuesday.

The articles from IDG News and The Christian Science Monitor said the Stuxnet worm was programmed to probe the hosts it infected for extremely specific settings. Unless it identified the hardware fingerprint it was looking for in industrial software systems made by Siemens, it remained largely dormant.

It was only after a unique configuration on a Programmable Logic Controller device was detected that Stuxnet took action. Under those circumstances, the worm made changes to a piece of Siemens code called Operational Block 35, which monitors critical factory operations, according to IDG, which cited Eric Byres, CTO of a firm called Byres Security.

IDG reported: “By messing with Operational Block 35, Stuxnet could easily cause a refinery's centrifuge to malfunction, but it could be used to hit other targets too, Byres said.”

“Stuxnet is essentially a precision, military-grade cyber missile deployed early last year to seek out and destroy one real-world target of high importance – a target still unknown,” The Christian Science Monitor said. It went on to say that the digital fingerprinting capability “shows Stuxnet to be not spyware, but rather attackware meant to destroy.”

Both reports said the sophistication of Stuxnet suggests Israel or some other nation state is behind the worm and both articles cited speculation by Langner that the intended target may have been Iran's Bushehr reactor, located about 750 miles from Tehran, that is under construction. The project faced reported delays around the same time Stuxnet is believed to have propagated, and the plant is believed to use the Windows-based Siemens software targeted in the attacks, IDG said.

The Christian Science Monitor said Stuxnet may already have exacted damage on Bushehr and noted the facility's expected opening in late August has been delayed for unknown reasons. ®